Arrowhead

I recently removed my exhaust system on my 91 C2 coupe for a valve adjustment. I was curious about the primary muffler as to whether it was straight through perferated/baffeled or chambered. I threw the muffler on the work bench and proceeded to run a steel wire through it. The wire went straight through and came out the other end so this told that it was not chambered. This muffler looks to be unmolested and original in every way. I have seen pictures and read posts about cutting open this muffler to remove the chambers. So the question is are some of these mufflers straight through and are some of us buying bypasses for no reason other than wieght savings?

garrett376

The wire methodology is a little crude to call this a conclusion/discovery! Its design is quite straight (not to mention perforated all over the place) so a wire should be able to get through there, especially given the angle it enters and exits from the curved entry and exit points! Get an endoscope, then report back!

Arrowhead

garrett376, if you dont mind I'm reporting back now. There was a post a few days ago " finally found the right sound". In that post I saw a picture of a primary muffler cut open and there is no way a wire will get through those chambers. I simply pushed the wire through with hardly any difficulty and it came out the other end and I could pull it back and forth without any binding. I would say the muffler is straight through but probably perferated and matted inside. Any doctors out there with an endoscope?

Marc Shaw

Rather than an endoscope, you could just get an inexpensive boroscope and take a look. I bought a cheap one for about $200 or you could just borrow one from an engine rebuilder or mechanic.

Marc

BlueHeeler

Or a flashlight and a (dental) mirror on a stick.

garrett376

Don't know if it matters to this investigation, but only one part number is listed in the PET for a primary muffler for all 3 models of engines M64/01/02/03.

911Jetta

This should answer the question...